


Dare

by orphan_account



Series: Sanscest Uncommon-pairs [3]
Category: Undertale (Video Game)
Genre: Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), M/M, Overstimulation, Truth or Dare, ink is enthusiastic but not much for social norms
Language: English
Status: Completed
Published: 2019-09-14
Updated: 2019-09-14
Packaged: 2020-10-18 20:47:12
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,749
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20645435
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: During a game of Truth or Dare, Killer gets dared to kiss Ink. Ink is incredibly enthusiastic about it.





	Dare

“Dust, truth or dare?”

Killer, Dust, also known as Murder, and Horror were playing Truth or Dare together. Nightmare was out doing who knew what, Cross had betrayed Nightmare so they couldn’t play with him anymore, and Error wasn’t fun to play with.

Dust stared into space, where he was probably seeing the phantom of his dead brother. “... Truth.”

“Would you kiss a Star Sans?” Horror asked, a smile stretching across his skull.

There was silence in the room as Dust and Killer turned to stare at Horror with identical, disgusted expressions.

“It was a legitimate question, okay!” Horror said. “It’s hard to find weird questions for truth! Now fess up. Dust, would you smooch a Star Sans?”

“... Yes.” Dust muttered. Killer and Horror wolf-whistled. “But only if I have to. And not with Blue.”

“So you and Ink, huh?” Killer asked. “Ooh, no, you and _Dream?_”

“Killer, truth or dare?” Dust cut in.

Killer’s grin widened at Dust’s non-answer but didn’t point it out. He didn’t want to fight Dust _again_. “Dare, duh. ‘Cause I’m not boring like _you_.”

“Next time we fight the Star Sanses,” and Killer already didn’t like where this was going, “You’re going to kiss Ink.”

“Ha! So it is Dream!” Killer crowed to mask his unease.

Dust rolled the lights in his eye sockets. “... You’re gonna have to kiss Ink, you know…”

“Eh.” Killer shrugged. “He’ll probably just freak out a little and it’ll be over.”

The ensuing looks from Dust and Horror made him doubt his own words a little, but not by much. After all, nothing would happen, right?

* * *

The next time the Star Sanses teleported in to stop an attack, a week had passed. The instant Killer spotted the multicolored light of one of Ink’s portals, he felt a thrill of excitement and nervousness.

“Stop right there!” Blue rattled off a cheesy line. “We are the Star Sanses and—”

“We know.” Horror said. “You’ve used this one on us three times already.”

Blue pouted. He launched himself at Horror in retaliation and soon, the battle had begun.

Dust appeared in front of Dream right afterwards, leaving Killer and Ink as the only outliers. Killer swallowed down the automatic response of teasing. He still had to kiss Ink, after all.

Ink sped towards Killer in an attack with his paintbrush. Killer easily dodged it with his higher LV and retaliated with a knife strike, which was blocked with the brush.

The battle dragged on, neither side overpowering the other. As they were all technically the same person, that made sense.

A lull came in the battle. Ink had a tired scowl on his face and his brush was dragging along the ground. Meanwhile, Killer still had his easygoing grin, smaller than a normal Sans’ but genuinely happy from the high of fighting a skilled opponent.

It was the perfect moment and Dust and Horror knew it, too. Neither initiated another volley, instead keeping Killer in their peripheral vision.

Killer was strangely looking forward to what he was about to do. He supposed it would be his greatest prank yet. That was all it was.

He darted forward. Ink flinched, closing his eye sockets.

“_Ink!_” His allies cried in fear.

But all Killer did was gently cradle the back of Ink’s skull and press a kiss to his teeth.

There was a moment of silence.

Then, Ink threw up black liquid all over Killer’s face.

“... Holy _crap_!” Horror started howling with laughter.

Dust cracked a rare smile and Blue clapped his hands to his own face. Dream just looked on, eye sockets glinting with stars as if he knew something no one else did.

Ink stayed frozen until Killer began to pull away. At the slightest separation, Ink grabbed Killer in a bridal carry and hopped through a portal to somewhere else.

Everyone left at the battlefield stood in an awkward silence.

Eventually, Horror spoke.

“What are we gonna tell Nightmare…?”

* * *

Once Killer blinked the rainbow-colored lights out of his vision, he found himself propped up on a pillow on Ink’s bed while the Creator himself licked his face and ground down on him with a summoned member.

“Wha…?” Killer moaned in surprise. He realized that Ink was lapping up the vomited ink on Killer’s face, but that didn’t explain why Ink was suddenly on top of him.

Once Ink finished cleaning Killer’s face, he stopped grinding on his pelvis and trailed downwards to pull off Killer’s shorts.

Ink’s tongue flicked around Killer’s pelvis and scraped along the bone. Having never been touched in such a way before, Killer arched up and a red cock soon sprang into existence.

Ink immediately latched onto the head. Killer grabbed fistfuls of the white sheets and yelped. Ink hummed in amusement around his cock, causing Killer to whimper and have to manually stop himself from thrusting up into Ink’s mouth.

Ink sucked the whole cock into his mouth with a wet sound. Killer’s vision went black for a moment. The movement wasn’t made any better by Ink beginning to slurp up and down his cock.

“T-too much—!” Killer cried. It was embarrassing, but he was already dangerously close.

Ink didn’t listen. He only sped up, grasping the base of the cock with a hand and rubbing firm circles on the underside. He tongued at the area just below the head and gently squeezed around the cock.

“Ah—!” Killer screamed as he came. His come was swiftly swallowed and stray drops licked off his cock like a popsicle. He was still oversensitive, so he jolted with every touch.

“I-Ink…?” Killer murmured, unusually timid as he tried to process. Of every reaction he’d anticipated to a simple kiss, Ink pushing him down and blowing both his cock and his mind certainly hadn’t been one of them.

“Sh…” Ink soothed. He lazily thumbed over the slit of Killer’s cock.

Ink grabbed one of Killer’s legs with his free hand and pulled it up over his shoulder. The new position left Killer wide open for Ink to dive down and stroke the back of his pelvis with his tongue.

Killer gasped, instinctively summoning a hole for the first time. Ink thrusted his tongue in as soon as it appeared, lapping at the walls. The sensation was new to Killer but arousing when paired with the finger still rubbing his cock.

The noises falling out of Killer’s mouth would normally have been humiliating, but he couldn’t care less with Ink inside of him. Ink’s tongue curled up and nudged at a bump in Killer’s walls that made him see stars.

At Killer’s shout, Ink seemed to decide he’d prepared enough and swung Killer’s other leg over his shoulder as well. Ink dragged his shorts down, exposing a fully-hard, prismatic cock. Killer shivered as finally caught on to what was about to happen.

Ink used cyan, magical saliva and similarly colored precome to lube his cock before lining it up with Killer’s hole. At the anticipation and nervousness, Killer’s breaths came out in harsh gasps.

“... You okay?” Ink asked with a worried look.

Killer threw his head back and laughed. “I’m having sex for the first time as the bottom of a _Star Sans_ and you just gave me a blowjob out of nowhere! I don’t think _anything_ is okay anymore!”

Ink was refusing to move, so Killer jerked Ink’s body down to make the head of his cock go into Killer’s hole. Ink groaned.

“But you know what? I’m totally fine with that!”

Ink still didn’t move and had a worried look on his face, so Killer jerked his pelvis up to sheathe Ink’s cock inside of him up to the base.

Ink doubled over with a cry. Beneath the pain and fullness of having Ink inside of him, Killer felt satisfaction. He smirked, rolling his hips and squeezing around Ink’s cock.

At the teasing movements, Ink couldn’t control himself anymore. He began shallowly thrusting, searching for the sweet spot inside Killer. Killer whined from the combination of pain and pleasure coming from going so fast already, his expression twisting a little.

Ink slowed again at this. Killer had been through way worse, though. He went through worse pain everyday.

“If you don’t speed the fuck up, I swear to _you_—” Killer wasn’t given a chance to finish the sentence.

Ink sped up. He angled his cock back to hit Killer’s prostate and pounded at it in quick succession. Killer screamed, clawing at his face with his hands as heat built up within his abdomen once more. His tears had been cleaned off when Ink had been licking his face, but tears began dripping down once more.

Ink pinned Killer’s wrists to the bed and kissed him, still rocking into his tight hole.

“Ngh, _Ink—_” Killer whined.

Ink smirked down at his capture while still rolling against Killer’s prostate. His eye-lights burned in heart shapes of lust.

“_ Ah— _!” Killer bit off his cry, coming in between them.

Ink growled at the tightening hole and how wrecked Killer sounded. He thrusted in to press up against Killer’s prostate and came in a thick stream right onto it.

At this point, Killer was reduced to moaning and hugging Ink tight. Through the haze, Ink realized what Killer was chanting.

“Ink, Ink, _Ink—_” Ink gave one last, teasing slap to the back of Killer’s pelvis before slipping out. They both hissed in a mixture of pleasure and oversensitivity.

Ink sighed blissfully, flopping down next to Killer and cuddling him. He immediately fell asleep. The pool of come on the sheets suddenly vanished without a trace.

Killer was tempted to fall asleep too, but he kept getting distracted by a single thought.

“... Am I in a relationship with _Ink_ now…?”

When he finally took a moment to take look around the room, he noticed that the walls were absolutely covered in sketches. Most of them were of him.

“... That’s not creepy at all.” Killer deadpanned. “Well, I guess I’m in a relationship with a Star Sans now.”

He was only getting more and more tired the longer he stayed awake, so he decided to just go to sleep already. He tucked both himself and Ink into the blank sheets. _The blank-ets_.

“Heh. Once a Sans, always a Sans.”

Right before he drifted off to fall asleep, Killer realized that it had seemed like Dust, Horror, Blue, and Dream had somehow already foreseen this outcome.

For some reason, it felt like he had been played…

**Author's Note:**

> Still one of the ones I wrote a year ago. I thought Killer and Ink had Same Energy so I decided to write them together


End file.
